The vast majority of goods shipped throughout the world are shipped via what are referred to as intermodal freight containers. As used herein, the term “container” includes any container (with or without wheels attached) that is not transparent to radio frequency signals, including but not limited to, intermodal freight containers. The most common international freight containers are known as International Standard Organization (ISO) dry intermodal containers, meaning they meet certain specific dimensional, mechanical and other standards issued by the ISO to facilitate global trade. These containers have specific dimensional, mechanical and other standards issued by the ISO to facilitate global trade by encouraging development and use of compatible standardized containers, handling equipment, ocean-going vessels, railroad equipment and over-the-road equipment throughout the world for all modes of surface transportation of goods. The are currently more than 12 million such containers in active circulation around the world as well as many more specialized containers such as refrigerated containers that carry perishable commodities. The United States alone receives approximately six million loaded containers per year, or approximately 17,000 per day, representing nearly half of the total value of the total value of all goods received each year. Since approximately 90% of all goods shipped internationally are moved in containers, container transport has become the backbone of the world economy.
Cargo loss due to theft has become a serious problem. Cargo is often misappropriated by shipping company employees, cargo handlers, and/or security personal. Many insurance professionals believe that more than half of all major cargo thefts are planned in logistics departments, by employees at the shipper or manufacturer who are thought to be trustworthy. Certain authorities believe that gangs operating in many metropolitan areas are actually training some of their members in logistics so that they will be eligible for employment at desirable trucking, warehousing or forwarding firms.
Because of the emergence of terrorist threats and activities, container security has become a national security issue. Terrorists are exploiting transportation modalities such as air, rail, truck-trailer, vessel-barge and bus. As evidenced by recent attacks, terrorists are directing, or seeking to direct, mobile transportation assets into office building and/or other heavily populated areas.
Shipping containers may also be used by terrorists for the arms shipments. Of greatest concern is the shipment of nuclear, chemical, or biological materials that can be used to produce weapons of mass destruction. Some of these materials are relatively small in size and could be hidden in shipping containers without being detected by governmental authorities. If such weapons were to fall into the wrong hands the results could be devastating.
With the above scenarios in mind, improving container security is desired. In one approach that is commonly in use, a locking mechanism or security seal are applied to container doors, to seal the cargo within the container. However, anyone who possesses the key or the combination, whether authorized or not, may gain access to the interior of a container. Further, the locks can be easily picked or removed by other means. Thus, locking devices are a limited deterrent to thieves or terrorists.
In another approach an electronic seal (“e-seal”) may be applied to a container. These e-seals are similar to traditional door seals and applied to the containers via the same, albeit weak, door hasp mechanism. These e-seals include an electronic device, such as a radio or radio reflective device, that can transmit the e-seal's serial number and a signal if the e-seal is cut or broken after installation. However, the e-seal does not communicate with the interior or contents of the container and does not transmit information related to the interior or contents to other devices.
The e-seal typically employs either a low power radio transceiver or uses radio frequency backscatter techniques to convey information from an e-seal to a reader installed at, for example, a terminal gate. The radio frequency backscatter technique involves use of a relatively expensive, narrow band, high-power radio technology based on a combination of radar and radiobroadcast technologies. The radio frequency backscatter technology requires that a reader send a radio signal of relatively high transmitted power (i.e., 0.5-3 W) that is reflected or scattered back to the reader with modulated or encoded data from the e-seal.
Furthermore, the e-seals are not effective at monitoring security of the container. For example, other methods of intrusion into the container may occur (e.g. breaching other parts of the container such as the side walls). Further, a biological agent may be implanted into the container through the container's standard air vents.